Method of fabricating collapsible tubes



June 1945- H. F. WATERS METHOD OF FABRICATING COLLAPSIBLE TUBES FiledJuly 30, 1942 2 Sheets-Sheet l INVENTOR. Harry fl Wafers June 5, 1945.H. F. WATERS METHOD OF FABRICATING COLLAPSIBLE TUBES Filed July 30, 19422 Sheets-Sheet 2 I IN V EN TOR. flaw/ y f. Wafer:

BY M Z2 .M

Patented June 5, 1945 UNITED STATES PATENT OFFlCE.

METHOD OF FABRICATING COLLAPSIBLE TUBES Harry F. Waters, New York, N. Y.

Application July 30, 1942, Serial No. 452,960

1 Claim. (Cl. 93-551) This invention relates to improvements in methodsand apparatus for forming collapsible tubes, and, more particularly, forcontinuously -treating cellulosic base tubulatures and applying thedispensing closures thereto.

The present invention, as intimated above, is directed to a continuousmethod and apparatus for fabricating and treating non-metalliccollapsible tubes, and desirably, tubes of cellulosic material of thetype known as reverted or regenerated cellulose. In my applicationsSerial No. 436,377, filed March 26, 1942, for Non-metallic dispensingtube and container; Serial No. 438,- 269, filed April 9, 1942, forDispensing tube; Serial No. 436,378, filed March 26, 1942, forCollapsible container; Serial No. 436,379 filed March 26, 1942, forCollapsible containers; Serial No. 438,- 270, filed April 9, 1942, forMoisture-vapor transmission resistant envelope package; Serial No.442,034, filed May 7, 1942, for Collapsible tube construction, therehave been shown a variety of novel dispensing tubes of revertedcellulose or other non-metallic materials, including dispense ingclosures and a variety of internal and external protective anddecorative coatings. The present disclosure is concerned primarily withmethods and means for carrying out the several forming, printing, dryingand coating steps of my said applications.

The features of novelty of the present invention will best be understoodby reference to the accompanying drawings, in which preferredfabrication steps are disclosed with reference to the apparatus suitabletherefor. vIn the drawings, like numerals refer to similar partsthroughout the several views, of which Fig. 1 is an elevation of anuntreated tube blank;

Fig. 2 is a view similar to Fig. 1 showing the application of printingto the tubulature;

Fig. 3 is a view of a wetted or imbibed tube blank mounted on a mandrelfor drying to shape;

Fig. 4 is an elevation, partly in broken section, of a tube shrunk inplace on a mandrel, and over a dispensing outlet;

Fig. 5 is an elevation of a plurality of mandrels mounted on a conveyor,and being transported through a drying oven;

Fig. 6 is a detail through the dispensing end of the tube of the typeshown in Fig. 4 with the upper end of the tube shrunk over the closuremember, and a clamping nut mounted on the dispensing nozzle;

Fig. 7 is a view similar to Fig. 6 showing the end of a tube shrunk toshape on the end of a plain mandrel;

Fig. 8 is a vertical section through a series 0 mandrels showing themanner of printing the tubes;

Fig. 9 is a view similar to Fig. 7 showing the rolling over of the endof a tube on the mandrel;

Fig. 10 is a horizontal elevation, partly. in section, of a tube with adispensing closure being blown off of a supporting mandrel;

Fig. 11 is a schematic view showing a method of introducing a dispensingnozzle in tubes of the type shown in Figs. 7 and 9;

Fig. 12 is a vertical elevation of an inverted, capped tube showing thecoating of the inside by filling with a fluid protecting agent;

Fig. 13 is a vertical section of a capbfid tube having an internalprotective coating applied by means of a spray, and

Fig. 14 is a broken vertical elevation of an 26 to adapt presentlyexisting mechanical set-ups forthe purpose. Collapsible tubes have beenmade with soft metals exclusively, and manufacturing steps in this fieldhave been developed around such soft metals. A feature of the presentinvention has been to devise process steps for the treatment ofnon-metallic tubes, .such as those of reverted cellulose, set out in myapplications, hereinabove identified. The process steps described hereinare developed around the controlling thought that, due to the waremergency, existing tube-treating equipment would have to be utilized,because new equipment was not available. 3

Considering the method and apparatus steps more specifically, and withparticular reference to the drawings, a tube I 0 of reverted cellulose,and of suitable dimensions, is extruded from a suitable machine, notshown, and subjected to a plasticizing and/or pickling step. Theregenerated cellulose may include 10 to 25 percent of a plasticizer,such as glycerine, and the pickling solution may be essentially anaqueous glycerine solution. In the pickling treatment the normally drytubes or pellicules soak up moisture and swell. Before pickling they mayhave suitable printing indicia printed thereover, as indicated at H inFig. 2.

When the tube blank It has been pickled sufliciently, or when it istaken off the extrusion machine, it may be mounted on a mandrel 20,which is carried on a spindle 2|. The pellicule or casing ill will beconsiderably oversized, leaving flns or margins II. This will beparticularly true if the blanks lo, have been flattened after extrusion,to permit printing and shipping inthe flat. The spindles 2| may becarried, in spaced relation, on a traveling chain or carrier 35, throughan oven to, where, under a suitable degree of heat, and, usually in thepresence of a current of air, the pellicule rapidly shrinks and conformsto the shape of 'the mandrel 20. Where a dispensing nozzle 50 is mountedat the free end of mandrel 20 and usually on a spindle 22, the open endI! of the casing l will shrink'thereon and thereover, all as indicatedin detail in Figs. 6 and '1. The dispensing nozzle 50 may comprise adisc section with nozzle outlet 52, having threads 53, and an aperture54. The member 50 will be seen to be of T-cross-section, with chamferedshoulders 55, terminating in a ring or annulus 56. A coacting plug ornut 51 is adapted to be screwed upon the threads 53 of the nozzle, andthis nut is provided with a rounded edge section 55 adapted to engageedge 55 in a ring or annular engagement and clamp the upper edge oroverhang of the tube In firmly in position. It will be noted that inaddition to the tube It being shrunk in place on section 5|, of thedispensing member, the upper portion is clamped between the two parts,of the closure. Due to the fact that the surface 55 is conical, andthat of 58 is spheroidal, there is a self-adjusting, line contacteifected by and between the cooperating parts of the closure,- withoutrequiring the clamping of any extended areas or portions of the tubemember II. Where the casing m is shrunk on a. mandrel without adispensing closure, the top section I! may be bent over, while the tubeis yet wet, by means of a forming roll 60. This step may take placewhile the mandrels are supported on the chaincarrier 30.

When lock nut 51 is screwed in place and the tube i0 is thoroughly dry,the tube may be blown off the mandrel by applying air to the tappednozzle 53. Thereafter a cap 59 may be applied to the tube, and thelatter waterproofed or otherwise treated, by inverting and filling witha proofing or coating material I0. Where several coats are to beapplied, such as an anchor coat and various proofing coats, the materialII will vary accordingly. Thus, wax or rubber compositions may beapplied, as well as nitrocellulose coatings, vinyl resins, gutta percha,and other materials.

Another method, as shown in Fig. 13, comprises introducing a tube 80,having a rosette or series of apertures 8| at the nip thereof, into thetube, and spraying the inside thereof. This type of operation isparticularly suited for use on the tubes when they are carriedhorizontally through an apparatus in the manner shown in Fig. 5. In suchcases the tube l0 may be caused to revolve rapidly, and the spray nozzle80 introduced into the closed end, when the spray is turned on, and thetube slowly withdrawn to the open end, when the spray is shut oil. Thetravel of the tube II is desirably wholly automatic. This centrifugalspraying is analogous to centrifugal casting of metals and results in adense, but thin, internal coat of uniform characteristics. The coatingsapplied in this manner are appreciably thinner than those obtained bydipping, and the finished job is smoother and much more even. Uponcompletion of the coating steps the tubes may be removed from themachine and hung up vertically for drainage of excess coating material12. The tubes may be externally coated, in any desired manner, bydipping or spraying, and the open bottom, may be provided with athermoplastic coating to permit heat-sealing, if the latter is desired,or, after the tubes are filled, they may be crimped or closed in theusual manner.

While the invention has been described above with respect totheshrinking of the tube on and over the closure member, the tube may beshrunk on a plain mandrel and the top edge turned or shaped, after whichthe dry tube is blown ofl the mandrel, and a closure 50 inserted intothe tube casing to assume the dotted line closing position shown in Fig.11. Thereafter the lock out 51 may be applied to complete the assembly.

In the printing of the tubes, as indicated in Fig. 8, a series ofmandrels 20, secured on carrying chain 30, and adapted to be rotatedthereby, are moved successively against a printing roll 90, having aprinting blanket 9| secured to the surface thereof. As the severalmandrels and printing roll counter-revolve in mutual contact, the tubesl0, shrunk to form on the mandrels, will be printed with the desiredindicia.

It will now be appreciated that there has been described a novel methodand apparatus for forming and treating collapsible tubes of revertedcellulose and like materials, and the necessary intermediate steps inthe treatment of such members, including printing, shaping, applicationof closures, drying and unitary or multiple coating steps necessary togive the desired finished product.

Having now particularly described and ascertained the nature of my saidinvention, and in what manner the same is to be performed, I declarethat what I claim is:

The method of forming collapsible dispensing tubes of reverted cellulosewhich comprises placing a wet oversize cellulose tube blank on a mandrelwith an excess of tube material extending over one end of the mandrel,subjecting said tube to controlled preliminary shrinking, rolling theshrunk'en but still damp tube over the end 7 of the mandrel to set thetube structure, completing the drying of the tube, removing the dry tubefrom the mandrel, pushing a shouldered dispensing nozzle into the tubeand into permanent contact with the formed shoulder of the tube, andsecuring the formed shoulder of the tube to the dispensing nozzle.

HARRY F. WATERS.

